No, I can't prove it's better than an AR. I have owned several, most were good, one was not. The trigger out of the box on the RDB is better than any I've had on my ARs but I don't know how it compares to any high end triggers. It's very light, easy to hold on target as for some reason recoil kind of pushes the barrel down instead of up. Better, I don't know how to decide that. I think maybe after I've owned it a few years and put a few more thousand rounds through it I could answer that better. However, I do, so far, think it's a viable option for someone wanting a good semi-auto in MA, and certainly cheaper than MA ARs. As for accuracy, I haven't had a chance to shoot mine at more than 100 yards, but with a plain jane Vortex red dot, I'm doing at least as well as any of my ARs did. I've been told already from one place that I can't use it in a carbine class, so I don't know if I'll be able to really judge it in that kind of situation either. I'm just curious about the RDB hate because "Kel Tec". I can't find forum after forum of people with mechanical failures or anything except someday it's going to break because "Kel Tec".
It's way behind the curve on accessories or spare parts, and yes, getting to the chamber from underneath is a pain in the ass but then I haven't had a failure of any kind in the 750 rounds I've fired in the short time I've had it, though. I had to tighten some screws in the stock, also. And I didn't clean it once, until after 750 rounds. And I'm using beat up metal preban mags. I'm wondering if there is some reason I don't know about that I shouldn't trust it with my life, but until then, I'm recommending it as a viable option to an AR or AK, especially in MA.
It has 4 sling attachment points on each side, no brass flying all over the place, light, barrel pushes slightly downward when fired, comfortable to hold and fire. So I'm guessing just not having 50 years of track record, yeah it doesn't beat that or the lego add ons. I'd love to have an X95, if it had as great of a trigger, and was about $1000 cheaper. But what's the advantage in the design? How is it mechanically better?